1. Field
The present invention relates to a printed circuit board having embedded capacitors and to a method of manufacturing the printed circuit board.
2. Description of the Related Art
While most printed circuit boards had discrete chip resistors or discrete chip capacitors mounted on the surface in the past, printed circuit boards having embedded passive components such as resistors and capacitors, etc., have recently been developed.
The technology for the printed circuit board having embedded passive components employs new materials and new processes to insert the passive components, such as resistors or capacitors, etc., into the exterior or interior of the board, so that these may replace the conventional chip resistors and chip capacitors.
That is, the printed circuit board having embedded passive components may have passive components, e.g. capacitors, buried in the outside or inner layers of the board itself. Regardless of the size of the board, if a capacitor, i.e. a passive component, is integrated as a part of the printed circuit board, it is referred to as an embedded capacitor, and the board is referred to as a capacitor-embedded PCB.
According to the related art, a capacitor-embedded printed circuit board may be manufactured by a set of processes including: partially etching the copper layer of a copper clad laminate (CCL) to form lower electrodes, stacking a dielectric layer and an upper conductive layer over the lower electrodes, and then etching the upper conductive layer to form upper electrodes.
Here, deviations may occur due to the etching, during the forming of the lower electrode, which may cause errors in the area of contact between the dielectric layer and the lower electrodes. As a result, errors may occur also in the capacitance value of the capacitor, creating problems in the reliability of the capacitor.
As such, there is a need for a capacitor-embedded printed circuit board and a manufacturing method thereof, with which the deviations in the contact area of the lower electrodes, caused by the etching during the process for forming the lower electrode, can be reduced.